A fluid control apparatus to be used for a semiconductor manufacturing device and the like has a structure in which various fluid control devices are placed in a plurality of rows, with passages of the fluid control devices on the adjacent rows being connected to each other at a predetermined position by device connecting means, and in recent years, in the fluid control apparatus of this kind, an attempt has been made to provide an integrated structure in which a mass-flow controller, a switching valve and the like are connected to one another without using tubes. In such a fluid control apparatus, a passage block (an upper-stage passage block) is placed on each of the two sides of a mass-flow controller and this is coupled with a block-shaped joint member (a lower-stage passage block) by two bolts from above (for example, Patent Document 1: Japanese Unexamined Patent Publication No. 8-326943).
In the above-mentioned fluid control apparatus, a number of processes are required upon attaching the upper-stage passage block to the lower-stage passage block; consequently, improving the efficiency of the bolt-fastening jobs, that is, in particular, positioning between a bolt insertion hole of the upper-stage passage block and a screw hole of the lower-stage passage block and a reduction in the number of bolts, becomes an important subject.
The objective of the present invention is to provide a coupling apparatus for passage blocks, which, upon attaching an upper-stage passage block to a lower-stage passage block, can easily carry out a positioning process between a bolt insertion hole of the upper-stage passage block and a screw hole of the lower-stage passage block, and also reduce the number of bolts.